A UPnP-based Decentralized Service Discovery Improved Algorithm

Transcription

1 Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol.1, No.1, Marc 2013, pp. 21~26 ISSN: A UPnP-based Decentralized Service Discovery Improved Algoritm Yu Si-cai*, Wu Yan-zi, Guo Run-niu Scool of Computer and Communication Lanzou University of Tecnology, Lanzou , Cina Troop 69050, Sawan , Cina Abstract Te current UPnP service discovery algoritm in te presence of te service can cause severe drops in te digital ome networ. Te reason is tat te root devices instantly send delay sending response messages and randomly selected independent response message congestion troug simulation analysis. To solve tese problems, an improved UPnP service discovery algoritm was given. Considering te lengt of te message and te bandwidt of te router, derived by testing te router te pacet loss rate can be reduced. Keywords: drop, service discovery, UPnP, queue size algoritm, best interval algoritm 1. Introduction Digital Home [1] networ refers to computer tecnology and networ tecnology as te foundation, all inds of ome appliances troug te different interconnection way communication and data excange, realize ouseold appliances between "te intercommunication", mae people never leave ome can be more convenient and quic access to information, tus greatly improve uman living comfort and entertaining. Home networs could consist of Information equipment, communications equipment, entertainment equipment, ome electric digital ome (Monitoring) device and electric ot water tables equipment, automation equipment, ligting equipment, security, ome alarm for elp equipment interconnection and management, as well as data and multimedia information saring. Te main purpose of te interconnection equipment sared networ services and resources, te remote call tem. Service discovery protocol [2] can effectively solve te device ow to automatically and effectively manage te problem of networed devices [3], a common coice UPnP service discovery algoritm [4]. However, wit te service in te digital ome networ gradually increased UPnP service discovery algoritms appear inefficient. Gribble [5] is trying to adopt a layered approac to solve te problem of Internet service discovery, tis approac, owever, ignores te "borderline" [6] of te ome networ environment. Cen Enyi et al [7] used in te UPnP root device (root devices) and te control point (control point) between a random delay is intermittently transmitted (RDCT) algoritms and sceduling delay instantaneous transmission (PDIT) algoritm, to some extent reduce te response to te news of te loss ratio, reducing te control point of te response message buffer size requirements. Asis T, et al [8] divide existing service discovery protocol into a "centralized" and "distributed", also acieved a certain effect on latency and networ traffic performance in service discovery. On tis basis, tis paper focuses on distributed small networ researc, using te improved algoritm of te size of te queue (Queue size Algoritm) and te best interval (Best interval Algoritm) algoritm to solve te service discovery message latency and pacet discard, in order to acieve a te service discovery smoot seamless connection. 2. Distributed Service Discovery Algoritm In te distributed service discovery model, te networ does not ave a directory server, te user and te service provider before broadcast communications. In tis researc, te application layer troug distributed computing to improve te rate of service discovery, te algoritm to be deployed in te active queue management (Active Queue Management, AQM), and te goal of te algoritm is: determine te router required transmission queue space and Received January 11, 2013; Revised Marc 3, 2013; Accepted Marc 18, 2013

2 22 ISSN: receive te next te outbrea of te news. Tis can be acieving by control te transmission rate of te service response. Te proposed algoritm includes instructions and interpreted message queue lengt required and two consecutive outbrea interval equation, in order to avoid tat te message will be discarded. OSI Open Systems Interconnection model, algoritm design at te application layer, protocol and application code, wic may cause te news, broe to te networ in terms of strategy. Te next rule requires eac computer routers send queue size or space, te router send queue and calculate te optimum interval must be available. Te algoritm was test in te case of distributed routers Queue Size Algoritm Te algoritm used to calculate te size of te sending queue for eac router, wic is illustrated in Pseudo code Algoritm 1. Te values m and n represent te number of clients and R services connected to Routers i respectively, were i 1, 2, Queue Size Algoritm. For i=1to No. of routers Start If(R i not connected to any node) SQsize Ri = Rim + Rin + 1. End 2.2. Best Interval Algoritm Assuming optionally te networ topology can be divided into rigt and left alves. In pseudo-code algoritm 2, equation to ensure best interval allows specific router receive te next burst message before forwarding all messages to te destination (client). Furter consider designated router queue sizes available, because it represents all te client (receiver) is connected to te router sared space between two or more continuous burst messages can be used to minimize te time required interval. Node z is number candidate routers. Message Size of service )) (1) Bandwidt tat message would use In Equation (1), te value of )) represents te maximum of ( Time ( x )). 1, 2,. j )) represents te lin time of message connection. Algoritm 2.pseudo code of interval algoritm Let te candidate routers C_R were =1,2 z. For = 1 to z Start Identify te two parts left and rigt of C_R. calculate te No. of services on left ( (Sl ) and on rigt( (SR (SR )). If(Lr > Rr ) else Large = Lr Large = Rr Calculate te best interval of CR : Large (BIC_R )= ))+ ))- )) (1) End for BI = 1 gaps Lr =1 =1 j For eac (BIC_R ) values = 1,2 z do te following: Start If ( BI < BIC_R ) End BI = BIC_R Rr =1 =1 gaps =1 )) : Represents te times of te number of message during te specific router does not receive messages from te nearest router. Wen tere is a service connected directly to te nearest router, it would require at least two message times to reac te router. IJEEI Vol. 1, No. 1, Marc 2013 : 21 26

3 IJEEI ISSN: Te following equations represent best interval for any router: Large gaps =1 =1 j (BIC_R )= ))+ ))- )) z. Te identified queue value by te routers can be used to minimize te BI value. Overlapped space (OS) value represents tis minimization. Pseudo code algoritm sows ow to calculate te OS. Pseudo code 3. calculation steps of OS Identy te router neigbor to cosen router and tis will be Rneigtbour. Let RLarge = Rneigbour. Let SQsize RLarge = sending queue size of RLarge Calculate OS = (SQsize - f(srlarge))/f(c ) (2) RLarge Ri n f(srlarge) = ( S ) represent te number of all services connected to 1 Rlarge. m f ( CRi) ( C ) represent all te number of client connect to Ri OS is measured from te 1 number of messages. It represents all te empty messages space in te sending queue of te cosen router. Equation (1)could use te OS value and be written as: Big gaps OS =1 =1 j =1 (BI) = T(x ) + T(x )-T(x )- T(x ) (3) And now te question is,all te routers in te networ must be evaluated in order to identify te best interval for te wole networ? Wic interval could be used for te networ? Te answer is: in a networ, not all routers must be evaluated, but part of te candidate as evaluation, te longest interval will eventually be used, because logic use te longest interval will be avoided in all oter routers on discarded news. Tere are some conditions can elp determine wic routers in deciding on te best value interval for maximum impact Te Rules of Coosing Candidate Router Te following rules indentify te bottlenecs of te messages flow pats. Tese rules required routers more time to forward te received messages during bursts: (1) Identify te longest pat between a client and service, and select te router wic is connected to tis client. (2) Identify te router wic connects te largest number to client and receives te largest number of services from anoter side of te networ. (3) Identify te router tat located nearest te end of te networ and is connected to one or more clients. If all te routers connected to a client, all te routers wic connect to te client must be selected in order to compare between two consecutive burst of messages tat reac tese routers consecutively. In te case of two (or more) consecutive bursts of te message is sent to te same client, and te client is separately connected to te router, wic means tat tere are two (or more) receiver logic connected to router, wic sould be in te calculation (OS) of te value wen considering. A client may meet more tan one of te previous conditions, in oter words, aving te longest pat and te client may be te same client, is connected to a router, wic receives te maximum number of services, it does not cause any problems. All candidate routers must be evaluated, te longest time interval is te best time interval in a networ, it can ensure tat no lost messages. A UPnP-based Decentralized Service Discovery Improved Algoritm (Yu Si-cai)

4 24 ISSN: Te Results Of Simulation Te application of simulation models clarify AQM on performing of UPnP. Tis was used to compare te algoritm, and under normal circumstances UPnP. Assume tat realistic application scenarios networ design includes four router (R0,R1,R2 and R3),in wic eac router connected to te tree services (S0, S1,..., and S9). Except R2 connected to six clients (C0, C1... C5).Te networ parameters are given in Table 1. (1) (C0,C1... C5) send multicast information on te networ to discover all services. (2) Te client sends a response message for all services requested. Algoritm, eac service separately any consecutive reply message witin a certain period of time. However, under normal circumstances, te service reply to te discovery request dependency. Tere are a UDP bacground traffic (S0, S8) and (S1 te S7), S0, S1 is connected to te R0, S7 and S8 connected to R3. Te bacwards flow rate is 0.01 and te message size is different. Routing rules based on te selected candidate, R2 is a candidate routers. Obviously, te service connect to R6 as te longest pat to reac te C0 and C1. Table 1. Networ Parameters Parameter name Value Bandwidt among routers (Main lins) 512Kb Bandwidt between routers and oter nodes (Sub lins) 256Kb Delay in main and sub 0ms Queue Type Drop Tail Routing Protocol DSDV Message Lengt of discovery(multicast) 64bytes Message Lengt of discovery reply(unicast) 128bytes Message Lengt of bac ward traffic 100,200,300bytes Simulation 100.0seconds R2 is: According to te size of te queue algoritm, te queue size for all te routers except SQsizeR0 41 5pacets,wile R2 21 3pacets In order to calculate te best interval, Overlapped Space(OS) must be calculated. OS (5 3) / messages spaces. All replying messages are different in te lin of bandwidt and equal in sizes: T x could be two values. ( ) 256*8 T( x ) 0.004s, 256*8 1 T( x ) 0.002s 512* *1024 Te Best Interval: ( BI) s. Te flowing Figure 1 and Figure 2 sow te networ utilization in algoritm and normal cases wen tis interval is applied in simulator. Growt enoug to receive burst in te next message is to forward all of te sudden news wen te news broe, te major part of te networ utilization is improved. Altoug te algoritm is to mae te calculation, in te case of using te algoritm to reac te upper limit of networ utilization will result in te loss of messages. Tis is because te algoritm does not tae into account te factors of te bacward message. IJEEI Vol. 1, No. 1, Marc 2013 : 21 26

5 IJEEI ISSN: Figure 1. Networ Utilization Comparison (Main Lin) Figure 2. Networ Utilization Comparison (Sub Lin) Te sub Lin results sow tat, under normal circumstances, tere are obvious differences, between normal case and using an algoritm, as is sown in Figure 2. Irrespective of active queue management in te utilization of te networ in te normal case to reac te upper limit and discard te message, wile in te case of using an algoritm, te networ utilization is less tan 85% and not discarded messages. Te previous figures sow tat te algoritm reduces discovery time by sending rate to avoid message loss. Tis ensures tat all messages to teir destination, witout loss of speed and efficiency. In addition, te figure also sows te impact of te bacward transport networ utilization and lost messages, tese must be considered in te algoritm to improve its performance. Figure 3 sows comparison AQM and under normal cases of te discovery rate. Overall, te service discovery algoritm uses a iger rate tan normal case. In te case of using an algoritm, te detection rate is between 77% -100%, and under normal cases, found 55% %. Figure 3. Discovery Rate Comparison 4. Conclusion During service discovery protocols, te router dropping messages results in incomplete discovery process, wic causes delay and inefficiency in connected nodes(s) performance. Tis algoritm solved tis problem. Tis algoritm introduces a new metod to te time interval required to determine te relationsip between te available spaces twice broe te news in te router queue. Tis indicates tat te specific metod to calculate te required transmit queue size. Tese metods can easily be modified to reduce te best interval by increasing te size of te queue and compete and vice versa. Tis algoritm tae te bandwidt of te networ A UPnP-based Decentralized Service Discovery Improved Algoritm (Yu Si-cai)

6 26 ISSN: configuration and size of te message in into consideration, tus affecting te rate of te transmission and reception. Previous experimental results sow tat te improved networ utilization discovery rate. In addition, tese Figures also sow tat te impact of te algoritm, te ratio of consumption of networ resources, wic indicates tat also need to provide te additional different parameters, te proposed algoritm available networ resources, in order to cope wit canging in te available networ. References [1] Yiaoumis Y, Huang T, Yap K, et al. Putting ome users in carge of teir networ. Systems and Infrastructure for te Digital Home, ACM Ubicomp worsop. 2012; 9: 1-6. [2] AlMejibli, Colley. Evaluating Transmission Time of Service Discovery Protocols by using NS2 Simulator. Wireless Advanced (WiAD). 2010; 11: [3] Intisar, Al-Mejibli, Martin, Colley. Enancing Service Discovery Performance over Home networs. Computer Networs & Communications (IJCNC). 2012; 4(2): [4] UPnP[EB/OL]. ttp://baie.baidu.com/view/27925.tm. [5] Gribble SD, Wels M, Beren RV, et al. Te Ninja arcitecture for robust Internet-scale systems and services. Computer Networs. 2001; 35(4): [6] Kind berg T, Fox A. System software for ubiquitous computing. Pervasive Computing. 2002; 1( 1): [7] Cen Enyi, SHI Yuancun, Xu Guang. UPnP service discovery algoritm performance analysis and improvement. Journal of Tsingua University. 2006; 46(4): [8] A sis T Bole, Sital Ranade. Approac of Association Rules Mining for Service Discovery in Mobile Adoc Networ. International Journal of Computer Applications. 2012; 44(8): IJEEI Vol. 1, No. 1, Marc 2013 : 21 26